My research is focused on regional climate variability in Europe and Asia from the past (last 2000 years) to the future (next 100 years), the effect of climate change on terrestrial and marine ecosystems, and the role of the large-scale circulation in the oceans and atmosphere on climate variability in these regions.

Using high-resolution proxies, mainly tree rings, I reconstruct past climate changes (e.g. temperatures, drought and precipitation, and the atmospheric circulation) on different temporal and spatial scales. My work has mainly been conducted in North Europe and China, but I have also projects in Canada and North Africa. These reconstructions are useful in understanding past climate variability under (more or less) natural conditions, i.e. before man had a significant impact on climate. Thus, these reconstructions can help us assess how much we have affected climate in the last century. Moreover, climate records going far back in time can help us better understand the climate system, e.g. how climate in different regions is related to that of other, remote, regions - teleconnections. Such teleconnections are due to the large-scale circulation in the oceans and the atmosphere, and this is a special focus of my research.

I also do research on contemporary climate change, presently directed towards better understanding the impacts (and feedbacks) of large-scale circulation change (e.g. the NAO and the Asian Monsoon) on climate in the future, but also on glacier variability in northern Scandinavia, changes in the growing season and the impact of climate change on marine ecosystems.